Work

Modeling and synthesis of bifunctional dual activation thiourea organocatalysts for Michael addition of pyrazole

Year: 2025

Type: article

Abstract: Modeling of Michael addition of pyrazole to cinnamaldehyde in the presence of six thiourea catalysts has been done at the DFT (B3LYP/6-31+G(d,p)) level. Four catalysts incorporating 2-pyridyl moiety are found to exhibit bifunctional dual activation by encapsulating pyrazole molecule in the cavity of cinnamaldehyde-catalyst complex thereby mimicking biosystem to bring the two reactants closer and also narrowing down the HOMO-LUMO gap. Guided by the theoretical results, four new N-bis(3,5-trifluoromethyl)phenyl-N’-2-pyridylthiourea catalysts were synthesized and well characterized on the basis of IR, 1 H and 13 C NMR and HRMS studies. X-ray crystal structure of one catalyst could also be done. On determining comparative catalytic efficacies of these catalysts experimentally for the model reaction of pyrazole with cinnamaldehyde, the catalyst N-bis(3,5-trifluoromethyl)phenyl-N’-2-(5-chloropyridyl)thiourea was found to be most effective, which is in accordance with the theoretical modeling results.

Source: Tetrahedron Green Chem

DOI: 10.1016/j.tgchem.2025.100081

Authors: Savita Sharma, Vandana Sharma, Sanjay Mandal, Raj K. Bansal

Institutions: Indian Institute of Science Education and Research Mohali, Inspiration Innovation Synergy University

Language: English

Topic: Asymmetric Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,850

Funder: Department of Science and Technology, Ministry of Science and Technology, India